目的:为全身CT设计多疾病分类扫描使用自动提取标签从放射科文reports.Materials和方法三个不同的器官系统:这项回顾性研究共有12,092例患者(平均年龄57 + - 18; 6172名妇女)包括对模型开发和测试(2012-2017自)。基于规则的算法被用来从12,092患者提取13667身体CT扫描19,225疾病的标签。使用三维DenseVNet,三个器官系统是分段的:肺和胸膜;肝胆;和肾脏及输尿管。对于每个器官,三维卷积神经网络分类没有明显的疾病与四种常见疾病为跨越所有三个模型总共15个不同的标签。测试是在相对于2875个手动导出的参考标签2158个CT体积的子集从2133名患者( - ; 1079名妇女18,平均年龄58 +)进行。性能报告为曲线(AUC)与通过方法德朗95%置信区间下接收器的操作特性的区域。结果:提取的标签说明书验证确认91%横跨15个不同的唱片公司99%的准确率。对于肺和胸膜标签的AUC分别为:肺不张0.77(95%CI:0.74,0.81),结节0.65(0.61,0.69),肺气肿0.89(0.86,0.92),积液0.97(0.96,0.98),并且没有明显的疾病0.89( 0.87,0.91)。对于肝和胆囊的AUC分别为:肝胆钙化0.62(95%CI:0.56,0.67),病变0.73(0.69,0.77),扩张0.87(0.84,0.90),脂肪0.89(0.86,0.92),并且没有明显的疾病0.82( 0.78,0.85)。对于肾脏及输尿管的AUC分别为:石0.83(95%CI:0.79,0.87),萎缩0.92(0.89,0.94),病变0.68(0.64,0.72),囊肿0.70(0.66,0.73),并且没有明显的疾病0.79(0.75 ,0.83)。结论:弱监督深度学习模型能够在多器官系统不同的疾病分类。
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肾细胞癌(RCC)是一种常见的癌症,随着临床行为的变化。懒惰的RCC通常是低级的,没有坏死,可以在没有治疗的情况下监测。激进的RCC通常是高级的,如果未及时检测和治疗,可能会导致转移和死亡。虽然大多数肾脏癌在CT扫描中都检测到,但分级是基于侵入性活检或手术的组织学。确定对CT图像的侵略性在临床上很重要,因为它促进了风险分层和治疗计划。这项研究旨在使用机器学习方法来识别与病理学特征相关的放射学特征,以促进评估CT图像而不是组织学上的癌症侵略性。本文提出了一种新型的自动化方法,即按区域(Corrfabr)相关的特征聚集,用于通过利用放射学和相应的不对齐病理学图像之间的相关性来对透明细胞RCC进行分类。 CORRFABR由三个主要步骤组成:(1)特征聚集,其中从放射学和病理图像中提取区域级特征,(2)融合,放射学特征与病理特征相关的放射学特征在区域级别上学习,并且(3)在其中预测的地方学到的相关特征用于仅使用CT作为输入来区分侵略性和顽固的透明细胞RCC。因此,在训练过程中,Corrfabr从放射学和病理学图像中学习,但是在没有病理图像的情况下,Corrfabr将使用CORFABR将侵略性与顽固的透明细胞RCC区分开。 Corrfabr仅比放射学特征改善了分类性能,二进制分类F1分数从0.68(0.04)增加到0.73(0.03)。这证明了将病理疾病特征纳入CT图像上透明细胞RCC侵袭性的分类的潜力。
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我们从一组稀疏的光谱时间序列中构建了一个物理参数化的概率自动编码器(PAE),以学习IA型超新星(SNE IA)的内在多样性。 PAE是一个两阶段的生成模型,由自动编码器(AE)组成,该模型在使用归一化流(NF)训练后概率地解释。我们证明,PAE学习了一个低维的潜在空间,该空间可捕获人口内存在的非线性特征范围,并且可以直接从数据直接从数据中准确地对整个波长和观察时间进行精确模拟SNE IA的光谱演化。通过引入相关性惩罚项和多阶段训练设置以及我们的物理参数化网络,我们表明可以在训练期间分离内在和外在的可变性模式,从而消除了需要进行额外标准化的其他模型。然后,我们在SNE IA的许多下游任务中使用PAE进行越来越精确的宇宙学分析,包括自动检测SN Outliers,与数据分布一致的样本的产生以及在存在噪音和不完整数据的情况下解决逆问题限制宇宙距离测量。我们发现,与以前的研究相一致的最佳固有模型参数数量似乎是三个,并表明我们可以用$ 0.091 \ pm 0.010 $ mag标准化SNE IA的测试样本,该样本对应于$ 0.074 \ pm。 0.010 $ mag如果删除了特殊的速度贡献。训练有素的模型和代码在\ href {https://github.com/georgestein/supaernova} {github.com/georgestein/supaernova}上发布
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前列腺癌是美国男人的第二致致命癌症。虽然磁共振成像(MRI)越来越多地用于引导前列腺癌诊断的靶向活组织检查,但其效用仍然受到限制,因为假阳性和假否定的高率以及较低的读者协议。机器学习方法在前列腺MRI上检测和定位癌症可以帮助标准化放射科学诠释。然而,现有的机器学习方法不仅在模型架构中不等,而且还可以在用于模型培训的地面真理标签策略中。在这项研究中,我们比较不同的标记策略,即病理证实放射科标签,整个安装组织病理学图像上的病理学家标签,以及病变水平和像素级数字病理学家标签(先前验证了组织病理学图像上的深层学习算法以预测像素 - 整个安装组织病理学图像上的Gleason模式)。我们分析这些标签对训练有素的机器学习模型的性能的影响。我们的实验表明,用它们培训的(1)放射科标签和模型可能会错过癌症,或低估癌症程度,(2)与他们培训的数字病理学家标签和模型与病理学家标签有高度的一致性,而(3)用数字病理学家培训的模型标签在两种不同疾病分布的两种不同群组中达到最佳性能,而不管使用的模型建筑如何。数字病理学家标签可以减少与人类注释相关的挑战,包括劳动力,时间,和读者间变异性,并且可以通过使可靠的机器学习模型进行培训来检测和定位前列腺癌,帮助弥合前列腺放射学和病理学之间的差距在MRI。
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专家(MOE)模型的混合物是对数据中的异质性建模的流行框架,由于其灵活性以及可用的统计估计和模型选择工具的丰富性,用于统计和机器学习中的回归和分类问题。这种灵活性来自于允许MOE模型中的混合物重量(或门控函数)与专家(或组件密度)一起取决于解释变量。与经典的有限混合物和回归模型的有限混合物相比,这允许由更复杂的数据生成过程产生的数据建模,该过程的混合参数与协变量无关。从计算的角度来看,当解释变量的数量可能大于样本量时,MOE模型在高维度中的使用是挑战的,尤其是从理论的角度来看,文献是对于统计估计和特征选择问题,仍缺乏处理维度诅咒的结果。我们考虑具有软马克斯门控函数和高斯专家的有限MOE模型,用于在异质数据上进行高维回归,并通过Lasso进行$ L_1 $调查的估计。我们专注于拉索估计属性,而不是其特征选择属性。我们在LASSO函数的正规化参数上提供了一个下限,该参数确保了根据Kullback-Leibler损失,Lasso估算器满足了$ L_1 $ -ORACLE不平等。
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In this paper, we propose a novel technique, namely INVALIDATOR, to automatically assess the correctness of APR-generated patches via semantic and syntactic reasoning. INVALIDATOR reasons about program semantic via program invariants while it also captures program syntax via language semantic learned from large code corpus using the pre-trained language model. Given a buggy program and the developer-patched program, INVALIDATOR infers likely invariants on both programs. Then, INVALIDATOR determines that a APR-generated patch overfits if: (1) it violates correct specifications or (2) maintains errors behaviors of the original buggy program. In case our approach fails to determine an overfitting patch based on invariants, INVALIDATOR utilizes a trained model from labeled patches to assess patch correctness based on program syntax. The benefit of INVALIDATOR is three-fold. First, INVALIDATOR is able to leverage both semantic and syntactic reasoning to enhance its discriminant capability. Second, INVALIDATOR does not require new test cases to be generated but instead only relies on the current test suite and uses invariant inference to generalize the behaviors of a program. Third, INVALIDATOR is fully automated. We have conducted our experiments on a dataset of 885 patches generated on real-world programs in Defects4J. Experiment results show that INVALIDATOR correctly classified 79% overfitting patches, accounting for 23% more overfitting patches being detected by the best baseline. INVALIDATOR also substantially outperforms the best baselines by 14% and 19% in terms of Accuracy and F-Measure, respectively.
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When robots learn reward functions using high capacity models that take raw state directly as input, they need to both learn a representation for what matters in the task -- the task ``features" -- as well as how to combine these features into a single objective. If they try to do both at once from input designed to teach the full reward function, it is easy to end up with a representation that contains spurious correlations in the data, which fails to generalize to new settings. Instead, our ultimate goal is to enable robots to identify and isolate the causal features that people actually care about and use when they represent states and behavior. Our idea is that we can tune into this representation by asking users what behaviors they consider similar: behaviors will be similar if the features that matter are similar, even if low-level behavior is different; conversely, behaviors will be different if even one of the features that matter differs. This, in turn, is what enables the robot to disambiguate between what needs to go into the representation versus what is spurious, as well as what aspects of behavior can be compressed together versus not. The notion of learning representations based on similarity has a nice parallel in contrastive learning, a self-supervised representation learning technique that maps visually similar data points to similar embeddings, where similarity is defined by a designer through data augmentation heuristics. By contrast, in order to learn the representations that people use, so we can learn their preferences and objectives, we use their definition of similarity. In simulation as well as in a user study, we show that learning through such similarity queries leads to representations that, while far from perfect, are indeed more generalizable than self-supervised and task-input alternatives.
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The latent space of autoencoders has been improved for clustering image data by jointly learning a t-distributed embedding with a clustering algorithm inspired by the neighborhood embedding concept proposed for data visualization. However, multivariate tabular data pose different challenges in representation learning than image data, where traditional machine learning is often superior to deep tabular data learning. In this paper, we address the challenges of learning tabular data in contrast to image data and present a novel Gaussian Cluster Embedding in Autoencoder Latent Space (G-CEALS) algorithm by replacing t-distributions with multivariate Gaussian clusters. Unlike current methods, the proposed approach independently defines the Gaussian embedding and the target cluster distribution to accommodate any clustering algorithm in representation learning. A trained G-CEALS model extracts a quality embedding for unseen test data. Based on the embedding clustering accuracy, the average rank of the proposed G-CEALS method is 1.4 (0.7), which is superior to all eight baseline clustering and cluster embedding methods on seven tabular data sets. This paper shows one of the first algorithms to jointly learn embedding and clustering to improve multivariate tabular data representation in downstream clustering.
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An unbiased scene graph generation (SGG) algorithm referred to as Skew Class-balanced Re-weighting (SCR) is proposed for considering the unbiased predicate prediction caused by the long-tailed distribution. The prior works focus mainly on alleviating the deteriorating performances of the minority predicate predictions, showing drastic dropping recall scores, i.e., losing the majority predicate performances. It has not yet correctly analyzed the trade-off between majority and minority predicate performances in the limited SGG datasets. In this paper, to alleviate the issue, the Skew Class-balanced Re-weighting (SCR) loss function is considered for the unbiased SGG models. Leveraged by the skewness of biased predicate predictions, the SCR estimates the target predicate weight coefficient and then re-weights more to the biased predicates for better trading-off between the majority predicates and the minority ones. Extensive experiments conducted on the standard Visual Genome dataset and Open Image V4 \& V6 show the performances and generality of the SCR with the traditional SGG models.
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In this paper we discuss the theory used in the design of an open source lightmorphic signatures analysis toolkit (LSAT). In addition to providing a core functionality, the software package enables specific optimizations with its modular and customizable design. To promote its usage and inspire future contributions, LSAT is publicly available. By using a self-supervised neural network and augmented machine learning algorithms, LSAT provides an easy-to-use interface with ample documentation. The experiments demonstrate that LSAT improves the otherwise tedious and error-prone tasks of translating lightmorphic associated data into usable spectrograms, enhanced with parameter tuning and performance analysis. With the provided mathematical functions, LSAT validates the nonlinearity encountered in the data conversion process while ensuring suitability of the forecasting algorithms.
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